I found my husband urinating in the kitchen sink ...

Perhaps you should ask your husband that question.

Absent another answer, I submit that perhaps he is plain lazy and has no class.

The next time he does this, take something he wants to eat, like a piece of fruit, and go wash it in the toilet.  Make sure he sees it (or at least tell him about it before he eats it).  Maybe he'll get the point.

maybe he has a bad sense of direction maybe you should put flashing arrow lights on the wall directing him to the bathroom

Hi Toni. I don't know the psychology behind his behavior, but if it's really disturbing you, hoist yourself up on the sink one day while he's home and let him see how odd that looks to use the sink as a toilet!

I'll share a weird thing with you too... My husband use to pee in bottles and stashed them under the bathroom sink! Well as you can imagine it freaked me out! I mean to the point that I was afraid to ask him what his malfunction was!  So what I did instead was start filling up bottles of my own pee and stashing them under the sink right next to his.  I can see how that might sound like a really strange way to handle it, but it worked... he poured them all out and I have never found another one of his pee bottle collections!

Some people's children.